Fluid meter



Sept. 29, 1942. c. HARDEBECQK 97,

FLUID METER Filed Nov.' 10, 1959 %new Patented Sept. 29, 1942 FLUm METERCarl Hardebeck, Aachen, Germany; vested in the Alien Property CustodianApplication November 10, 1939, Serial No. 303,895 In Germany November 4,1938 2 Claims.

Part-flow quantity passed gauges are. known, in which in the mainconduit a stationary throttling device or an adjustable throttlingdevice which in this case is equipped with a scale is mounted and aflow-meter is provided in a bypass of the main conduit so that the twoflows are in a predetermined constant proportion to one another and thesmaller flow is then directly measured. The quantity passed gauge canconsist for instance of a nozzle in combination with ringscales.

The present invention has for its object, to avoid in arrangements ofthe above mentioned kind, when alterations of the state of the mediumoccur, any recalculation and correction or special adjustings ofapparatus elements and to obtain, in spite of the fluctuations of thestate, always a clear indication of the quantity passed, for instancerelated to the normal state. I

The effect of this arrangement will be hereinafter explained by anexample.

The quantity passed through the throttle of the main conduit follows thelaws for the quantity passed through nozzles and therefore V=A Vfi if Vis the quantity passed, A a constant and h the pressure difierence onthe throttle.

The capillary tube, which according to the invention is mounted in theby-pass conduit, does not follow, as regards quantity passed, the abovelaw but the Poiseuville law, and the passed quantity V1 is therefore, ifb is a constant decisive for the.by-pass conduit and it again thepressure .I

difierence V1=b h. The instrument may, for instance, be calibrated forair of atmospheric pressure and the flow through the main conduit maamount at a certain gauge pressuredifierence to m. /h. If then air oi? 1atmosphere pressureis conducted through the instrument at the samepressure difference, the quantity passing through the conduit amountsthen to 10 m. /h. V air of two atmospheres absolute, or, recalculated toatmospheric pressure, to

I scale is mounted.

shown in Fig. 1, comprising further a recording.

The flow meter in the by-pass conduit may 5.

be adjusteq so that the quantity passed relation of main conduit andby-pass conduit amounts to I 100: 1. When air from atmospheric pressureflows through the apparatus, the through-flow is then i to the volume 10in /11., the through-flow in the by-pass being, however, of 1 atmosphereoverpressure or 2 atmospheres absolute. This 10 ]./h. air of 2atmospheres absolute produce in the flow meter gauge foratmosphericpressure an indication of 1414 l./h., as the indication ofthe flow takes place according to the nozzle law.

The through-flow through the main conduit amounts, relative to theatmospheric pressure to 10x /2-14.14 m./h. The indication of the flowmeter shows therefore multiplied with the constant relation factor thethrough-flow quantity through the main conduit.

This calculation may be repeated for all pressures in a similar manner.The instrument therefore always shows the quantity related to the normalcondition, independent of pression.

In the example mentioned above the main throttle was assumed to bestationary, so that the diiferent quantities passed were indicated bydifferent positions of the quantity passed auge.

The possibility of applying this quite novel measuring apparatus is veryextensive. For measuring the quantity passed any quantity passed gaugesof known type can serve, such as ring-scales, difference pressure metersand so forth, proyided the pressure consumption of the quantity passedgauge is keptsmall in proportion to that of the capillary tube. Theindications of the quantity passed guages can evidently be used also forrecording'and regulating.

In the accompanying drawing two embodi ments of the invention areillustrated by way of example.

Fig. 1 shows an arrangement, in which in the by-pass conduit to the mainconduit a the capillary tube e and as quantity passed gauge an orificeplate I: in connection with an indicator 1 for the difference pressureconstructed as a ring 2 shows a construction similar to that device mfor recording the quantity oi,gas relative to the normal conditio Iclaim:

1. A fluid meter, comprising in combination, a

main conduit, 9. throttle in the main conduit, a by-pass conduitcommunicating at its ends with the main conduit on opposite sides ofsaid throttle, a flow meter in saidby-pass conduit, 9, capiliary tube inthe by-pass conduit, the pressure drop of the flow meter being lowcompared to the diil'erential pressure across the capillary tube, theflow meter consisting of an orifice plate and a ringscale correlatedwith said orifice plate.

'2. A fluid meter as specified in claim 1, wherein the ringscale isprovided with a recording device. 7

' CARL' HARDEBECK.

the com-

